Each cylinder of an internal combustion engine is equipped with one or more gas exchange valves (e.g., intake and exhaust valves) that are cyclically opened during normal operation to allow fuel and air into the engine and to discharge exhaust from the engine. In a conventional engine, the valves are opened by way of a camshaft/rocker arm arrangement. The camshaft includes one or more lobes oriented at particular angles corresponding to desired lift timings and amounts of the associated valves. The cam lobes are connected to stem ends of the associated valves by way of the rocker arm and associated pushrod linkage. As the camshaft rotates, the cam lobes come into contact with a first pivoting end of the rocker arm, thereby forcing a second pivoting end of the rocker arm against the stem ends of the valves. This pivoting motion causes the valves to lift or open against a spring bias. As the cam lobes rotate away from the rocker arm, the valves are released and allowed to return to their closed positions. An exemplary system for moving the gas exchange valves is disclosed in U.S. Pat. No. 8,210,144 of Langewisch that published on Jul. 3, 2012.
Most diesel engines manufactured today can be classified as one of several common types, for example a common rail engine, a HEUI (Hydraulically operated Electronically actuated Unit Injector) engine, a MUI (Mechanically operated Unit Injector) engine, or a MEUI (Mechanically operated Electronicaly actuated Unit Injector). These engines are classified based on the type of fuel injector and fuel system used in the engine. Due to differences between these types of engines, the space inside each cylinder head and valve actuation requirements may be different for each engine. Accordingly, each of these types of engines has historically had a unique valve actuation system.
Although the unique valve actuation systems described above may function adequately for their intended applications, they can also be problematic. In particular, many different parts must be designed, stocked, and distributed for each of the different systems, which can be costly. In addition, it may be difficult to keep track of and maintain the different systems. Accordingly, resources may be limited for use in pursuing new or improved designs.
The valve actuation system of the present disclosure is directed towards overcoming one or more of the problems set forth above and/or other problems of the prior art.